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A Universe from Nothing

I finally finished the book. It’s fairly short — please note that Summitis twice as long and a quarter of the price, and it contains absolutely no equations (although I’ll admit it has lots of Russian names to keep track of).

The first part of the book is an overview of the current state of cosmology — suffice it to say that things are looking weirder and weirder, and the more scientists find out space and time and matter and energy, the more difficult it becomes to present a tidy narrative like the Big Bang of why things are the way they are. Much of this material was also covered in the Yale astronomy course I listened to, but that doesn’t mean I can understand it at even the most general level. I certainly can’t judge whether Krauss is right. He seems to have the credentials, although anyone who would write a book calledThe Physics of Star Trek has some ‘splainin’ to do (although it could be a great book, for all I know).

Krauss discusses the ramifications of modern cosmological research in the second part of the book. So:

Something from nothing. This is the key discussion. There is now a scientific approach to understanding “creation” — how something comes from nothing. It will undoubtedly not satisfy theologians, but putting creation ex nihilo within the reach of scientific explanation means that theologians and philosophers become irrelevant to the discussion.

The anthropic principle. This is the puzzling concept that physical laws seem fine-tuned for our existence. If some of the baseline constants of the universe were even slightly different, life couldn’t have formed and we wouldn’t be here to measure those constants and ponder this puzzling concept. Another way of thinking about this is Einstein’s famous question: “What I want to know is whether God had any choice in the creation of the universe.” (What Einstein meant by God is not what theologians mean byGod.) That is, do the laws of nature have to be what they are? If not, why are they what they are?

The trendy cosmological response to this is the theory of multiverses, which Krauss supports. There are lots of universes, goes the theory, maybe an infinite number, of which ours is just one. Krauss says:

[I]n discussions with those who feel the need for a creator, the existence of a multiverse is viewed as a cop-out conceived by physicists who have run out of answers–or perhaps questions. This may eventually be the case, but it is not so now. Almost every logical possibility we can imagine regarding extending laws of physics as we know them, on small scales, into a more complete theory, suggests that, on large scales, our universe is not unique.

(That final sentence is not one of Krauss’s better ones.) If ours is not unique, then there is nothing special about the laws that govern it — they just happen to be ones that allow for the development of intelligent life.

Of course, to make this science, the multiverse theory has to be testable — and how can you test it if you can’t see or experience or measure anything outside our own little universe? So is it science? This guy, at any rate, doesn’t think so.

Here is Krauss’s summary of his book:

We have discovered that all signs suggest a universe that could and plausibly did arise from a deeper nothing–involving the absence of space itself–and which may one day return to nothing via processes that may not only be comprehensible but also processes that do not require any external control or direction. In this sense, science, as physicist Steven Weinberg has emphasized, does not make it impossible to believe in God, but rather makes it possible to not believe in God. Without science, everything is a miracle. With science, there remains the possibility that nothing is. Religious belief in this case becomes less and less necessary, and also less and less relevant.